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1 /*
2  * jcmaster.c
3  *
4  * This file was part of the Independent JPEG Group's software:
5  * Copyright (C) 1991-1997, Thomas G. Lane.
6  * Modified 2003-2010 by Guido Vollbeding.
7  * libjpeg-turbo Modifications:
8  * Copyright (C) 2010, 2016, 2018, D. R. Commander.
9  * For conditions of distribution and use, see the accompanying README.ijg
10  * file.
11  *
12  * This file contains master control logic for the JPEG compressor.
13  * These routines are concerned with parameter validation, initial setup,
14  * and inter-pass control (determining the number of passes and the work
15  * to be done in each pass).
16  */
17 
18 #define JPEG_INTERNALS
19 #include "jinclude.h"
20 #include "jpeglib.h"
21 #include "jpegcomp.h"
22 #include "jconfigint.h"
23 
24 
25 /* Private state */
26 
27 typedef enum {
28   main_pass,                    /* input data, also do first output step */
29   huff_opt_pass,                /* Huffman code optimization pass */
30   output_pass                   /* data output pass */
31 } c_pass_type;
32 
33 typedef struct {
34   struct jpeg_comp_master pub;  /* public fields */
35 
36   c_pass_type pass_type;        /* the type of the current pass */
37 
38   int pass_number;              /* # of passes completed */
39   int total_passes;             /* total # of passes needed */
40 
41   int scan_number;              /* current index in scan_info[] */
42 
43   /*
44    * This is here so we can add libjpeg-turbo version/build information to the
45    * global string table without introducing a new global symbol.  Adding this
46    * information to the global string table allows one to examine a binary
47    * object and determine which version of libjpeg-turbo it was built from or
48    * linked against.
49    */
50   const char *jpeg_version;
51 
52 } my_comp_master;
53 
54 typedef my_comp_master *my_master_ptr;
55 
56 
57 /*
58  * Support routines that do various essential calculations.
59  */
60 
61 #if JPEG_LIB_VERSION >= 70
62 /*
63  * Compute JPEG image dimensions and related values.
64  * NOTE: this is exported for possible use by application.
65  * Hence it mustn't do anything that can't be done twice.
66  */
67 
68 GLOBAL(void)
jpeg_calc_jpeg_dimensions(j_compress_ptr cinfo)69 jpeg_calc_jpeg_dimensions(j_compress_ptr cinfo)
70 /* Do computations that are needed before master selection phase */
71 {
72   /* Hardwire it to "no scaling" */
73   cinfo->jpeg_width = cinfo->image_width;
74   cinfo->jpeg_height = cinfo->image_height;
75   cinfo->min_DCT_h_scaled_size = DCTSIZE;
76   cinfo->min_DCT_v_scaled_size = DCTSIZE;
77 }
78 #endif
79 
80 
81 LOCAL(void)
initial_setup(j_compress_ptr cinfo,boolean transcode_only)82 initial_setup(j_compress_ptr cinfo, boolean transcode_only)
83 /* Do computations that are needed before master selection phase */
84 {
85   int ci;
86   jpeg_component_info *compptr;
87   long samplesperrow;
88   JDIMENSION jd_samplesperrow;
89 
90 #if JPEG_LIB_VERSION >= 70
91 #if JPEG_LIB_VERSION >= 80
92   if (!transcode_only)
93 #endif
94     jpeg_calc_jpeg_dimensions(cinfo);
95 #endif
96 
97   /* Sanity check on image dimensions */
98   if (cinfo->_jpeg_height <= 0 || cinfo->_jpeg_width <= 0 ||
99       cinfo->num_components <= 0 || cinfo->input_components <= 0)
100     ERREXIT(cinfo, JERR_EMPTY_IMAGE);
101 
102   /* Make sure image isn't bigger than I can handle */
103   if ((long)cinfo->_jpeg_height > (long)JPEG_MAX_DIMENSION ||
104       (long)cinfo->_jpeg_width > (long)JPEG_MAX_DIMENSION)
105     ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int)JPEG_MAX_DIMENSION);
106 
107   /* Width of an input scanline must be representable as JDIMENSION. */
108   samplesperrow = (long)cinfo->image_width * (long)cinfo->input_components;
109   jd_samplesperrow = (JDIMENSION)samplesperrow;
110   if ((long)jd_samplesperrow != samplesperrow)
111     ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
112 
113   /* For now, precision must match compiled-in value... */
114   if (cinfo->data_precision != BITS_IN_JSAMPLE)
115     ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
116 
117   /* Check that number of components won't exceed internal array sizes */
118   if (cinfo->num_components > MAX_COMPONENTS)
119     ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
120              MAX_COMPONENTS);
121 
122   /* Compute maximum sampling factors; check factor validity */
123   cinfo->max_h_samp_factor = 1;
124   cinfo->max_v_samp_factor = 1;
125   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
126        ci++, compptr++) {
127     if (compptr->h_samp_factor <= 0 ||
128         compptr->h_samp_factor > MAX_SAMP_FACTOR ||
129         compptr->v_samp_factor <= 0 ||
130         compptr->v_samp_factor > MAX_SAMP_FACTOR)
131       ERREXIT(cinfo, JERR_BAD_SAMPLING);
132     cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor,
133                                    compptr->h_samp_factor);
134     cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor,
135                                    compptr->v_samp_factor);
136   }
137 
138   /* Compute dimensions of components */
139   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
140        ci++, compptr++) {
141     /* Fill in the correct component_index value; don't rely on application */
142     compptr->component_index = ci;
143     /* For compression, we never do DCT scaling. */
144 #if JPEG_LIB_VERSION >= 70
145     compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size = DCTSIZE;
146 #else
147     compptr->DCT_scaled_size = DCTSIZE;
148 #endif
149     /* Size in DCT blocks */
150     compptr->width_in_blocks = (JDIMENSION)
151       jdiv_round_up((long)cinfo->_jpeg_width * (long)compptr->h_samp_factor,
152                     (long)(cinfo->max_h_samp_factor * DCTSIZE));
153     compptr->height_in_blocks = (JDIMENSION)
154       jdiv_round_up((long)cinfo->_jpeg_height * (long)compptr->v_samp_factor,
155                     (long)(cinfo->max_v_samp_factor * DCTSIZE));
156     /* Size in samples */
157     compptr->downsampled_width = (JDIMENSION)
158       jdiv_round_up((long)cinfo->_jpeg_width * (long)compptr->h_samp_factor,
159                     (long)cinfo->max_h_samp_factor);
160     compptr->downsampled_height = (JDIMENSION)
161       jdiv_round_up((long)cinfo->_jpeg_height * (long)compptr->v_samp_factor,
162                     (long)cinfo->max_v_samp_factor);
163     /* Mark component needed (this flag isn't actually used for compression) */
164     compptr->component_needed = TRUE;
165   }
166 
167   /* Compute number of fully interleaved MCU rows (number of times that
168    * main controller will call coefficient controller).
169    */
170   cinfo->total_iMCU_rows = (JDIMENSION)
171     jdiv_round_up((long)cinfo->_jpeg_height,
172                   (long)(cinfo->max_v_samp_factor * DCTSIZE));
173 }
174 
175 
176 #ifdef C_MULTISCAN_FILES_SUPPORTED
177 
178 LOCAL(void)
validate_script(j_compress_ptr cinfo)179 validate_script(j_compress_ptr cinfo)
180 /* Verify that the scan script in cinfo->scan_info[] is valid; also
181  * determine whether it uses progressive JPEG, and set cinfo->progressive_mode.
182  */
183 {
184   const jpeg_scan_info *scanptr;
185   int scanno, ncomps, ci, coefi, thisi;
186   int Ss, Se, Ah, Al;
187   boolean component_sent[MAX_COMPONENTS];
188 #ifdef C_PROGRESSIVE_SUPPORTED
189   int *last_bitpos_ptr;
190   int last_bitpos[MAX_COMPONENTS][DCTSIZE2];
191   /* -1 until that coefficient has been seen; then last Al for it */
192 #endif
193 
194   if (cinfo->num_scans <= 0)
195     ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, 0);
196 
197   /* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1;
198    * for progressive JPEG, no scan can have this.
199    */
200   scanptr = cinfo->scan_info;
201   if (scanptr->Ss != 0 || scanptr->Se != DCTSIZE2 - 1) {
202 #ifdef C_PROGRESSIVE_SUPPORTED
203     cinfo->progressive_mode = TRUE;
204     last_bitpos_ptr = &last_bitpos[0][0];
205     for (ci = 0; ci < cinfo->num_components; ci++)
206       for (coefi = 0; coefi < DCTSIZE2; coefi++)
207         *last_bitpos_ptr++ = -1;
208 #else
209     ERREXIT(cinfo, JERR_NOT_COMPILED);
210 #endif
211   } else {
212     cinfo->progressive_mode = FALSE;
213     for (ci = 0; ci < cinfo->num_components; ci++)
214       component_sent[ci] = FALSE;
215   }
216 
217   for (scanno = 1; scanno <= cinfo->num_scans; scanptr++, scanno++) {
218     /* Validate component indexes */
219     ncomps = scanptr->comps_in_scan;
220     if (ncomps <= 0 || ncomps > MAX_COMPS_IN_SCAN)
221       ERREXIT2(cinfo, JERR_COMPONENT_COUNT, ncomps, MAX_COMPS_IN_SCAN);
222     for (ci = 0; ci < ncomps; ci++) {
223       thisi = scanptr->component_index[ci];
224       if (thisi < 0 || thisi >= cinfo->num_components)
225         ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
226       /* Components must appear in SOF order within each scan */
227       if (ci > 0 && thisi <= scanptr->component_index[ci - 1])
228         ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
229     }
230     /* Validate progression parameters */
231     Ss = scanptr->Ss;
232     Se = scanptr->Se;
233     Ah = scanptr->Ah;
234     Al = scanptr->Al;
235     if (cinfo->progressive_mode) {
236 #ifdef C_PROGRESSIVE_SUPPORTED
237       /* Rec. ITU-T T.81 | ISO/IEC 10918-1 simply gives the ranges 0..13 for Ah
238        * and Al, but that seems wrong: the upper bound ought to depend on data
239        * precision.  Perhaps they really meant 0..N+1 for N-bit precision.
240        * Here we allow 0..10 for 8-bit data; Al larger than 10 results in
241        * out-of-range reconstructed DC values during the first DC scan,
242        * which might cause problems for some decoders.
243        */
244 #if BITS_IN_JSAMPLE == 8
245 #define MAX_AH_AL  10
246 #else
247 #define MAX_AH_AL  13
248 #endif
249       if (Ss < 0 || Ss >= DCTSIZE2 || Se < Ss || Se >= DCTSIZE2 ||
250           Ah < 0 || Ah > MAX_AH_AL || Al < 0 || Al > MAX_AH_AL)
251         ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
252       if (Ss == 0) {
253         if (Se != 0)            /* DC and AC together not OK */
254           ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
255       } else {
256         if (ncomps != 1)        /* AC scans must be for only one component */
257           ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
258       }
259       for (ci = 0; ci < ncomps; ci++) {
260         last_bitpos_ptr = &last_bitpos[scanptr->component_index[ci]][0];
261         if (Ss != 0 && last_bitpos_ptr[0] < 0) /* AC without prior DC scan */
262           ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
263         for (coefi = Ss; coefi <= Se; coefi++) {
264           if (last_bitpos_ptr[coefi] < 0) {
265             /* first scan of this coefficient */
266             if (Ah != 0)
267               ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
268           } else {
269             /* not first scan */
270             if (Ah != last_bitpos_ptr[coefi] || Al != Ah - 1)
271               ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
272           }
273           last_bitpos_ptr[coefi] = Al;
274         }
275       }
276 #endif
277     } else {
278       /* For sequential JPEG, all progression parameters must be these: */
279       if (Ss != 0 || Se != DCTSIZE2 - 1 || Ah != 0 || Al != 0)
280         ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
281       /* Make sure components are not sent twice */
282       for (ci = 0; ci < ncomps; ci++) {
283         thisi = scanptr->component_index[ci];
284         if (component_sent[thisi])
285           ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
286         component_sent[thisi] = TRUE;
287       }
288     }
289   }
290 
291   /* Now verify that everything got sent. */
292   if (cinfo->progressive_mode) {
293 #ifdef C_PROGRESSIVE_SUPPORTED
294     /* For progressive mode, we only check that at least some DC data
295      * got sent for each component; the spec does not require that all bits
296      * of all coefficients be transmitted.  Would it be wiser to enforce
297      * transmission of all coefficient bits??
298      */
299     for (ci = 0; ci < cinfo->num_components; ci++) {
300       if (last_bitpos[ci][0] < 0)
301         ERREXIT(cinfo, JERR_MISSING_DATA);
302     }
303 #endif
304   } else {
305     for (ci = 0; ci < cinfo->num_components; ci++) {
306       if (!component_sent[ci])
307         ERREXIT(cinfo, JERR_MISSING_DATA);
308     }
309   }
310 }
311 
312 #endif /* C_MULTISCAN_FILES_SUPPORTED */
313 
314 
315 LOCAL(void)
select_scan_parameters(j_compress_ptr cinfo)316 select_scan_parameters(j_compress_ptr cinfo)
317 /* Set up the scan parameters for the current scan */
318 {
319   int ci;
320 
321 #ifdef C_MULTISCAN_FILES_SUPPORTED
322   if (cinfo->scan_info != NULL) {
323     /* Prepare for current scan --- the script is already validated */
324     my_master_ptr master = (my_master_ptr)cinfo->master;
325     const jpeg_scan_info *scanptr = cinfo->scan_info + master->scan_number;
326 
327     cinfo->comps_in_scan = scanptr->comps_in_scan;
328     for (ci = 0; ci < scanptr->comps_in_scan; ci++) {
329       cinfo->cur_comp_info[ci] =
330         &cinfo->comp_info[scanptr->component_index[ci]];
331     }
332     cinfo->Ss = scanptr->Ss;
333     cinfo->Se = scanptr->Se;
334     cinfo->Ah = scanptr->Ah;
335     cinfo->Al = scanptr->Al;
336   } else
337 #endif
338   {
339     /* Prepare for single sequential-JPEG scan containing all components */
340     if (cinfo->num_components > MAX_COMPS_IN_SCAN)
341       ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
342                MAX_COMPS_IN_SCAN);
343     cinfo->comps_in_scan = cinfo->num_components;
344     for (ci = 0; ci < cinfo->num_components; ci++) {
345       cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci];
346     }
347     cinfo->Ss = 0;
348     cinfo->Se = DCTSIZE2 - 1;
349     cinfo->Ah = 0;
350     cinfo->Al = 0;
351   }
352 }
353 
354 
355 LOCAL(void)
per_scan_setup(j_compress_ptr cinfo)356 per_scan_setup(j_compress_ptr cinfo)
357 /* Do computations that are needed before processing a JPEG scan */
358 /* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */
359 {
360   int ci, mcublks, tmp;
361   jpeg_component_info *compptr;
362 
363   if (cinfo->comps_in_scan == 1) {
364 
365     /* Noninterleaved (single-component) scan */
366     compptr = cinfo->cur_comp_info[0];
367 
368     /* Overall image size in MCUs */
369     cinfo->MCUs_per_row = compptr->width_in_blocks;
370     cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
371 
372     /* For noninterleaved scan, always one block per MCU */
373     compptr->MCU_width = 1;
374     compptr->MCU_height = 1;
375     compptr->MCU_blocks = 1;
376     compptr->MCU_sample_width = DCTSIZE;
377     compptr->last_col_width = 1;
378     /* For noninterleaved scans, it is convenient to define last_row_height
379      * as the number of block rows present in the last iMCU row.
380      */
381     tmp = (int)(compptr->height_in_blocks % compptr->v_samp_factor);
382     if (tmp == 0) tmp = compptr->v_samp_factor;
383     compptr->last_row_height = tmp;
384 
385     /* Prepare array describing MCU composition */
386     cinfo->blocks_in_MCU = 1;
387     cinfo->MCU_membership[0] = 0;
388 
389   } else {
390 
391     /* Interleaved (multi-component) scan */
392     if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)
393       ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
394                MAX_COMPS_IN_SCAN);
395 
396     /* Overall image size in MCUs */
397     cinfo->MCUs_per_row = (JDIMENSION)
398       jdiv_round_up((long)cinfo->_jpeg_width,
399                     (long)(cinfo->max_h_samp_factor * DCTSIZE));
400     cinfo->MCU_rows_in_scan = (JDIMENSION)
401       jdiv_round_up((long)cinfo->_jpeg_height,
402                     (long)(cinfo->max_v_samp_factor * DCTSIZE));
403 
404     cinfo->blocks_in_MCU = 0;
405 
406     for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
407       compptr = cinfo->cur_comp_info[ci];
408       /* Sampling factors give # of blocks of component in each MCU */
409       compptr->MCU_width = compptr->h_samp_factor;
410       compptr->MCU_height = compptr->v_samp_factor;
411       compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
412       compptr->MCU_sample_width = compptr->MCU_width * DCTSIZE;
413       /* Figure number of non-dummy blocks in last MCU column & row */
414       tmp = (int)(compptr->width_in_blocks % compptr->MCU_width);
415       if (tmp == 0) tmp = compptr->MCU_width;
416       compptr->last_col_width = tmp;
417       tmp = (int)(compptr->height_in_blocks % compptr->MCU_height);
418       if (tmp == 0) tmp = compptr->MCU_height;
419       compptr->last_row_height = tmp;
420       /* Prepare array describing MCU composition */
421       mcublks = compptr->MCU_blocks;
422       if (cinfo->blocks_in_MCU + mcublks > C_MAX_BLOCKS_IN_MCU)
423         ERREXIT(cinfo, JERR_BAD_MCU_SIZE);
424       while (mcublks-- > 0) {
425         cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
426       }
427     }
428 
429   }
430 
431   /* Convert restart specified in rows to actual MCU count. */
432   /* Note that count must fit in 16 bits, so we provide limiting. */
433   if (cinfo->restart_in_rows > 0) {
434     long nominal = (long)cinfo->restart_in_rows * (long)cinfo->MCUs_per_row;
435     cinfo->restart_interval = (unsigned int)MIN(nominal, 65535L);
436   }
437 }
438 
439 
440 /*
441  * Per-pass setup.
442  * This is called at the beginning of each pass.  We determine which modules
443  * will be active during this pass and give them appropriate start_pass calls.
444  * We also set is_last_pass to indicate whether any more passes will be
445  * required.
446  */
447 
448 METHODDEF(void)
prepare_for_pass(j_compress_ptr cinfo)449 prepare_for_pass(j_compress_ptr cinfo)
450 {
451   my_master_ptr master = (my_master_ptr)cinfo->master;
452 
453   switch (master->pass_type) {
454   case main_pass:
455     /* Initial pass: will collect input data, and do either Huffman
456      * optimization or data output for the first scan.
457      */
458     select_scan_parameters(cinfo);
459     per_scan_setup(cinfo);
460     if (!cinfo->raw_data_in) {
461       (*cinfo->cconvert->start_pass) (cinfo);
462       (*cinfo->downsample->start_pass) (cinfo);
463       (*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU);
464     }
465     (*cinfo->fdct->start_pass) (cinfo);
466     (*cinfo->entropy->start_pass) (cinfo, cinfo->optimize_coding);
467     (*cinfo->coef->start_pass) (cinfo,
468                                 (master->total_passes > 1 ?
469                                  JBUF_SAVE_AND_PASS : JBUF_PASS_THRU));
470     (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);
471     if (cinfo->optimize_coding) {
472       /* No immediate data output; postpone writing frame/scan headers */
473       master->pub.call_pass_startup = FALSE;
474     } else {
475       /* Will write frame/scan headers at first jpeg_write_scanlines call */
476       master->pub.call_pass_startup = TRUE;
477     }
478     break;
479 #ifdef ENTROPY_OPT_SUPPORTED
480   case huff_opt_pass:
481     /* Do Huffman optimization for a scan after the first one. */
482     select_scan_parameters(cinfo);
483     per_scan_setup(cinfo);
484     if (cinfo->Ss != 0 || cinfo->Ah == 0 || cinfo->arith_code) {
485       (*cinfo->entropy->start_pass) (cinfo, TRUE);
486       (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
487       master->pub.call_pass_startup = FALSE;
488       break;
489     }
490     /* Special case: Huffman DC refinement scans need no Huffman table
491      * and therefore we can skip the optimization pass for them.
492      */
493     master->pass_type = output_pass;
494     master->pass_number++;
495     /*FALLTHROUGH*/
496 #endif
497   case output_pass:
498     /* Do a data-output pass. */
499     /* We need not repeat per-scan setup if prior optimization pass did it. */
500     if (!cinfo->optimize_coding) {
501       select_scan_parameters(cinfo);
502       per_scan_setup(cinfo);
503     }
504     (*cinfo->entropy->start_pass) (cinfo, FALSE);
505     (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
506     /* We emit frame/scan headers now */
507     if (master->scan_number == 0)
508       (*cinfo->marker->write_frame_header) (cinfo);
509     (*cinfo->marker->write_scan_header) (cinfo);
510     master->pub.call_pass_startup = FALSE;
511     break;
512   default:
513     ERREXIT(cinfo, JERR_NOT_COMPILED);
514   }
515 
516   master->pub.is_last_pass = (master->pass_number == master->total_passes - 1);
517 
518   /* Set up progress monitor's pass info if present */
519   if (cinfo->progress != NULL) {
520     cinfo->progress->completed_passes = master->pass_number;
521     cinfo->progress->total_passes = master->total_passes;
522   }
523 }
524 
525 
526 /*
527  * Special start-of-pass hook.
528  * This is called by jpeg_write_scanlines if call_pass_startup is TRUE.
529  * In single-pass processing, we need this hook because we don't want to
530  * write frame/scan headers during jpeg_start_compress; we want to let the
531  * application write COM markers etc. between jpeg_start_compress and the
532  * jpeg_write_scanlines loop.
533  * In multi-pass processing, this routine is not used.
534  */
535 
536 METHODDEF(void)
pass_startup(j_compress_ptr cinfo)537 pass_startup(j_compress_ptr cinfo)
538 {
539   cinfo->master->call_pass_startup = FALSE; /* reset flag so call only once */
540 
541   (*cinfo->marker->write_frame_header) (cinfo);
542   (*cinfo->marker->write_scan_header) (cinfo);
543 }
544 
545 
546 /*
547  * Finish up at end of pass.
548  */
549 
550 METHODDEF(void)
finish_pass_master(j_compress_ptr cinfo)551 finish_pass_master(j_compress_ptr cinfo)
552 {
553   my_master_ptr master = (my_master_ptr)cinfo->master;
554 
555   /* The entropy coder always needs an end-of-pass call,
556    * either to analyze statistics or to flush its output buffer.
557    */
558   (*cinfo->entropy->finish_pass) (cinfo);
559 
560   /* Update state for next pass */
561   switch (master->pass_type) {
562   case main_pass:
563     /* next pass is either output of scan 0 (after optimization)
564      * or output of scan 1 (if no optimization).
565      */
566     master->pass_type = output_pass;
567     if (!cinfo->optimize_coding)
568       master->scan_number++;
569     break;
570   case huff_opt_pass:
571     /* next pass is always output of current scan */
572     master->pass_type = output_pass;
573     break;
574   case output_pass:
575     /* next pass is either optimization or output of next scan */
576     if (cinfo->optimize_coding)
577       master->pass_type = huff_opt_pass;
578     master->scan_number++;
579     break;
580   }
581 
582   master->pass_number++;
583 }
584 
585 
586 /*
587  * Initialize master compression control.
588  */
589 
590 GLOBAL(void)
jinit_c_master_control(j_compress_ptr cinfo,boolean transcode_only)591 jinit_c_master_control(j_compress_ptr cinfo, boolean transcode_only)
592 {
593   my_master_ptr master;
594 
595   master = (my_master_ptr)
596     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
597                                 sizeof(my_comp_master));
598   cinfo->master = (struct jpeg_comp_master *)master;
599   master->pub.prepare_for_pass = prepare_for_pass;
600   master->pub.pass_startup = pass_startup;
601   master->pub.finish_pass = finish_pass_master;
602   master->pub.is_last_pass = FALSE;
603 
604   /* Validate parameters, determine derived values */
605   initial_setup(cinfo, transcode_only);
606 
607   if (cinfo->scan_info != NULL) {
608 #ifdef C_MULTISCAN_FILES_SUPPORTED
609     validate_script(cinfo);
610 #else
611     ERREXIT(cinfo, JERR_NOT_COMPILED);
612 #endif
613   } else {
614     cinfo->progressive_mode = FALSE;
615     cinfo->num_scans = 1;
616   }
617 
618   if (cinfo->progressive_mode && !cinfo->arith_code)  /*  TEMPORARY HACK ??? */
619     cinfo->optimize_coding = TRUE; /* assume default tables no good for progressive mode */
620 
621   /* Initialize my private state */
622   if (transcode_only) {
623     /* no main pass in transcoding */
624     if (cinfo->optimize_coding)
625       master->pass_type = huff_opt_pass;
626     else
627       master->pass_type = output_pass;
628   } else {
629     /* for normal compression, first pass is always this type: */
630     master->pass_type = main_pass;
631   }
632   master->scan_number = 0;
633   master->pass_number = 0;
634   if (cinfo->optimize_coding)
635     master->total_passes = cinfo->num_scans * 2;
636   else
637     master->total_passes = cinfo->num_scans;
638 
639   master->jpeg_version = PACKAGE_NAME " version " VERSION " (build " BUILD ")";
640 }
641